As device geometries shrink it is becoming increasingly important to look at alternatives for titanium as a contact/barrier material. For example, as contact holes or vias (i.e., very small openings located, for example, between surface conductive paths and or "wiring" and active devices on underlying layers) become narrower and deeper, they are harder to fill with metal. Also, metalorganic sources for titanium nitride, for example, which is used as a metallization barrier, are particularly difficult to find that have sufficiently low and stable resistance to be suitable for very small contacts. Furthermore, it is difficult to deposit pure titanium by chemical vapor deposition at low temperatures because currently available precursors require high temperatures to remove halogen from films deposited from titanium halides or are contaminated with carbon when common metalorganic precursors are used.
Thus, there is a continuing need for methods and precursor compositions for the deposition of titanium and metals that are suitable replacements for titanium in metal-containing films, on substrates such as those used in semiconductor structures, particularly using vapor deposition processes.